Most Helpful Guy
Ultimatums are never a good thing, he will either call your bluff and end things for good or he will give in out of fear and your relationship will now be based on you using your love as a weapon to hurt and manipulate him.
In either case you have probably just hurt him rather badly, might be good to work on communication skills together if you get the chance or solo if you don't.
Most Helpful Girl
This is a sure switch from what I am usually used to seeing, where the poor girl is having problems with a sporadic man, not wanting a relationship. I see here, this time, the shoe is now on the other foot, and it is you who is not putting 'your best foot forwards" in this "hanging by a thread" relationship.
I am a bit confused, if you will excuse me. If you are not able now to find the time in the relationship at present, then how on earth do you expect to find time in a more permanent one, may I ask?
My advice to you, is start working and nurturing the one you have at present, and if that is doable, then work on a more futuristic and---realistic relationship.
In the mean time, if you both are fighting like cats and dogs now, and only one of you is putting real effort into this relationship, then, along with no communication or compromise, this will not even make it to the next level, called "hereafter."
You both need to really sit down and, instead of texting, not talking, get everything out in the open, and come to some happy median, before you lose site of each others' respect and---your relationship together.
Don't keep yourself up all night with this. You can always send another text for the road now, and tell him that this is just silly, and that maybe when you BOTH have the time, it's time kiss and make up and to---make it all better.xx